The present invention relates to an exhaust gas system for an internal combustion engine, especially of a commercial vehicle.
The present application proceeds from DE 103 22 963 A1, FIGS. 2A and 2C of which disclose an exhaust gas system of a multi-cylinder internal combustion engine, according to which the exhaust gas outlets of a portion of the cylinders communicate with a first exhaust gas manifold section, and the exhaust gas outlets of the other portion of the cylinders communicate with a second exhaust gas manifold section, whereby a catalytic converter is disposed in each of the exhaust gas manifold sections. However, this document provides no discussion regarding the type of catalytic converters that are disposed in the individual exhaust gas manifold sections. DE 101 23 359 A1 discloses in FIG. 21 and the associated text the provision of a muffler in an exhaust gas manifold, whereby a hydrolysis catalytic converter, and at least one oxidation catalytic converter, can have flow through them in parallel in the muffler. A reduction agent is metered into the inlet region of the hydrolysis catalytic converter, with ammonia being produced by the reaction agent. The oxidation catalytic converter serves for the conversion of NO into NO2. This type of adjacent arrangement of two catalytic converters in the muffler, which is a preliminary muffler, can leave undesired, non-uniform flow through the muffler, which can effect either an NO2 production that is too high, or a non-complete conversion of the reduction agent accompanied by harmful separation products such as isocyanic acid or solid cyanuric acid particles.
It is therefore an object of the present invention to provide an exhaust gas post treatment device in an exhaust gas system of an internal combustion engine of the aforementioned general type, according to which, due to the selection and arrangement of the catalytic converters, the problems that can occur with the parallel arrangement of the catalytic converters in the muffler of DE 101 23 359 A1 are eliminated.